Plasmon announced back in November of 2003, the UDO technology as a new standard for professional optical storage, aimed at both large and small companies looking for an easy archival storage system. Based on ultra density, phase change blue laser technology, it is the recognized successor to 5.25 inch MO (Magneto Optical) storage and is available in both Rewritable and true Write Once media formats. Our review has the goal of introducing UDO technology, and to trial how it works.